Switch assembly



G. A. REESE SWITCH ASSEMBLY July 19, 1960 2 Sheets-Sheet 1 Filed April15, 1957 July 19, 1960. G. A. REESE I 2,945,931

SWITCH ASSEMBLY Filed April 15, 1957 2 sheetssheet 2 United StatesPatent O 2,945,931 swrrcir ASSEMBLY Glenn A. Reese, Canoga lark,Cali-f., Yassigner to The Magnavox Company, Los Angeles, Calif., acorporation of Delaware Filed Apr. 15, 1957, Ser. No. 652,968 "zzClaims. (ci. zoo-9o) The present invention 'relates to a switchingassembly which is capable of repeatedly performing a plurality ofsuccessive swiching operations at an extremely high rate of speed and oflaccomplishing this without the concomitant production of noise or othertransient parasitic signals.

The switching assembly of the. invention finds general utility in theelectrical and electronic arts. In these arts, the requirement for highspeed multiple-type switches frequently occurs. For example, high speedmultiple switches nd general utility as channel selectors in many typesof present day digital` computers. YIn fact,- the switching asemblies ofthe type with which the present` in.- vention is concerned finds utilityin any application where rapid multiple switching or commutator actionis required.

.The high speed switching assembly to be described in f the followingspecitication uses a plurality of individual switching units. Theindividual units are `adapted to be operated from one operational stateto another by means of `an external magnetic field. Each of the unitsincludes a magnetic armature which is constrained to move from one fixedcontact in the particular unit to another for double-throw operations.This movement of the armature is under the control of the externalmagnetic iield, and this movement is eifectuatedby variations in theiield. In like manner, the armature can be made to make or break with asingle fixed contact, for single-throw action, in response to variationsin the external magnetic field.

The switching assembly to be described includes a magnetic structurewhich defines an annular air gap. The individual switching units arepositioned in this yair gap. A magnetic yfield is produced in the airgap which rotates with respect to the individual switching units, and.this iield is caused to exhibit radial shifts or variations atdifferent positions around the air gap. As the magnetic eld sweeps pastthe various switching units, these eld variations periodically actuatethe armatures in the units. In this manner, a succession of switchingoperations is achieved for each rotational cycle of the magnetic iield.The number of these switching operations in each cycle depends, ofcourse, upon the number of individual switching units that arepositioned in the air gap. Moreover, these successive switchingoperations are repeated for each rotational cycle of the magnetic iield.

The speed with' which the successive switching operations of theassembly may be carried out will be appreciated when it is realized thatthe magnetic iield may be produced by a magnetic structure which may beappropriately coupled to an electric motor for rotation. Therefore, therotational speed of the magnetic iield can be of a relatively highorder. Then, by placing a plurality of individual switching units in theannular air gap between these rings, a large number of successive andrepeated individual switching operations can be conveniently carriedout. v

A `feature of the invention' is the provision of aswitching assembly ofthe type described above which is so conj 2,945,931 Patented July 19,1960 structed that switch-actuating variations in a rotating magneticfield may be precisely located Iand sharply defined. This per-mitstheassembly to be designed and constructed so as to provide an exactrelationship between the instantaneous angular positions of the rotatingmagnetic iield and the'correspo'nding actuation of the switching units.This enables accurate timing of the switch actuations to be realized.Such accurate timing is` an essential requirernent in most present dayuses of multiple cyclic switches. -Y Another essential requirement thatis met by the switching assembly of thepresent invention is that of highspeed switching operation without the accompanying production ofundesired noisesignals and other extraneous interference. Such unwantedsignals are generally due tocontact 'bounce and to unwanted vibrationsof the armatures in the individual switching units. The assembly o'ifthe present invention operates positively toactuate each individual unitwithout setting up vibrations in the units so that the generation ofsuch unwanted noise as a by-product of the switching action is avoided.Moreover, the structure and operation of the assembly constituting theinvention is such that the individual switching units may beconveniently damped, for example, by a hydraulic uid, further topreclude any tendency for the switch armatures to vibrate and create theundesired noise signals.

From -a mechanical aspect, the switching assembly of the invention hasthe desirable features of relatively low wear, and this results inextremely long and trouble-free operation. Moreoventhe assembly isrelatively simple and inexpensive to construct land operate.

In the drawings where are to be considered as merely illustrative of oneembodiment of the invention: l

Figure 1` is a side viewjof one constructed embodiment of the switchingassembly :of the invention on a somewhat reduced scale, and showsapparatus, including a drive motor for producing a desired rotationalmotion of a magnetic eld to successively actuate a plurality ofindividual switching units which are included in the assembly;

Figure 2 is a top plan view of the switching assembly on the same scaleas Figure l, and'showing a pair of annular members. which are positionedto 'form `an annular air gap, and lthis viewialso shows a plurality ofmagnets whichy create a magnetic ux in the air gap controlling theindividual switching units ,which extend into the annular air gap atvarious positions around the assembly;

Figure 3 is a sectional ,view substantially on the line 3-3 of FigurevZto showthe mounting of magnets which are'usedto create the ux in theannular air gap;

Figure 4 is a view, partly in section and partly in phantom and on anenlarged scale with respect to the views of Figures l and 2, of one ofthe individual switching units used in the assembly and its relation toa typical one of the magnets shown in Figure 2; and

Figures 5A and 5B are fragmentary top plan views which schematicallyillustrate the action of an armature in the individual switching unitshown in Figure 4 as the magnetic flux, in the air gap is swept past thearmature'such that `the armature is actuated between first and secondfixed contacts in the switching unit.

The switching assembly of the illustrated embodiment of the inventionincludes an electric motor 10 which is supported on an appropriatesupporting surface 12 and which is preferably a synchronous motor. Theelectric motor includes a drive shaft 14. This drive shaft extendsupwardly in -a substantially vertical direction, and it is secured to aturntable 16 to `impart rotational motion to the'turntable. Theturntable 16 is disposed in a horizontal plane, and it is composed of anon-magnetic material such as, for example, aluminum. The diameter ofthe turntable may be of the order of 9 inches.

The turntable 16 supports a pair of annular members 18 and 20. Theseannular members are supported in spaced, nested uni-planar andconcentric relation, and they are also spaced from the turntable 16. Aseries of blocks composed, for example, of aluminum and designated as 22are secured to the turntable and to the respective annular members 18and 20. These blocks rigidly support the annular members 18 and20 on theturntable 16, with the annular members lying in a plane above theturntable and parallel to the plane of the turntable.

The annular members 18 and 2-0 may be composed of a magnetic materialsuch as, for example, cold rolled steel. These members define an annularair gap 24 between the outer peripheral edge of the member 18' and theinner peripheral edge of the member 20. The member 18, for example, mayhave-an in-ner diameter of 6.3 inches and an outer diameter of 7.5inches. The annular member 20, on the other hand, may have an innerdiameter of 7.75 inches and an outer diameter of 8.7 inches.

It is evident that when the motor is energized, its drive shaft rotatesthe turntable 16 which, in turn, causes the annular members 18 and 20 torotate.

The annular member 18 has a series of channels 26 formed as notches inits outer peripheral edge. Each of these channels extends axially alongthe outer peripheral edge of the annular member 18 and each has apredetermined radial depth. These channels are placed 4 56. The units 52are disposed at selected angular positions about the turntable 16. Itwill be understood that as many switching units 52 are used as it isdesired to have successive switching operations `for each cycle ofrotation of the turntable 16 and of the annular members 18 and 20.

Details of one of the switching units 52 are shown in Figure 4. The unitmay contain a tubular outer casing 58 which is preferably composed of anon-magnetic, electrically conductive material such as brass. The unitis supported so that this housing extends vertically down into theannular air gap 24 of Figure 2. An armature 60 is mounted in the casingS8, and this armature may be composed of a magnetic material such assoitiron. The

v to the casing. Since the armature is composed of a magat selectedangular positions around the annular member 18.

A plurality of permanent U-shaped magnets, such as the magnet 28 inFigure 3, lare secured to the turntable 1 6 by screws such as the screw30 in Figure 3. These permanent magnets are positioned to correspond tothe angular positions of the channels 26 in the peripheral edge of theannular member 18, and one of the permanent magnets is located at each such channel. Each U- shaped magnet 28 has a pair of spaced parallellegs, and these legs extend upwardly from the turntable 16 intorespective engagement with the `annular members 18 and 20. One of thelegs represents a south pole, and the other leg represents a north pole.These legs may be secured respectively to the annular members 18 and 28*by a pair of screws 34.

The permanent magnets 28 are oset radially with respect to the annularmembers 18 and 20 so that the leg associated with the annular member isdisplaced inwardly from that member and projects into the. annular airgap 24. Likewise, the leg 'associated with the annular member 18 engagesthat member at the base of the corresponding one of the channels 2.6.

The permanent magnets 28 cooperate with the an nular members 18 and 20to produce a magnetic liux in the annular `air gap 24. The lines of theresulting mag netic eld extend in a radial direction from the annularmember 20 which constitutes the north pole to the annular member 18which constitutes the south pole.

TheV `fact that the permanent magnets 28 are offset inwardly in the.illustrated manner, `and the provision of the channels 26 in the outerperipheral edge of the annular member 18, create well-deiined andprecisely lo.- Ycated shifts or variations in the magnetic flux in theair gap 24 at the regions of the individual channels 26. Therefore, asthe turntable 16 and the annular members y18 and 20 with theirassociated magnets 28 are rotated by the motor 10, the resulting flux inthe annular air gap 214 also rotates.

As shown in Figure l, the top of the motor 1t) projects through astationary supporting table 50, and the turntable 16 land annular rings18 and 2t) are supported for rotation on the upper side of the table.The table 50 forms a convenient support for a plurality of stationaryindividual switching units 52 which extend into the annularair gap 24 ofFigure 2. Each of the switching units netic material, it is susceptibleto extraneousmagnetic fields which enterV through the non-magneticcasing 58, and such fields cause the armature to move in one direci tionor another against the resilience of the wire 62. In the illustratedembodiment, the armature tapers upwardly and has a contact portion 60aat its upper extremity. This contact portion is composed, for example,of 24 carat gold.

The tubular casing 58 may have an inner diameter of the order of .O67Iinch `and an outer diameter of the order of .083 inch. The resilientwire 62 may, ffor example, -be a piece of piano wire of .010 inchdiameter. The armature 69 may have a diameter of .065 inch at ,its base,and its contact portion 60a may have a diameter o' .025 inch and alength of .050 inch.

The switchingunit S2 is supported in the annular ai-r gap 24 by the@bracket 54 in such a position 'that the north pole of each of theU-shaped magnets 28 passes within about .014 inch from the armature asthe turni table `16 is rotated. The tubular casing 58 has an upperportion 66 composed, for example, of an electrically conductivenon-magnetic material such as brass. A pair of .fixed contacts 68 and'78 are supported in mutually insulated relation in a plastic compound72 .in that por# tion. These ycontacts extend throughA the `plasticcom-` pound and protrude in spaced parallel rela-tion to 'be dis# posedon opposite sides of the armature contact por tion 60a.

Each of the fixed contacts 68 and 78 may be composed of 24 carat gold,and they may have a diameter of, for example, .032 inch. These contactsmay extend about 3/32 of Ian inch below the plastic 72, and theircontact area may 'be attened to have a width of about .O45 inch.Suitable electrical connections may be made to -each of the fixedcontacts 68 and 78 .by appropriate external terminals. Connection to thearmature 68 is made -by way of a termin-al 74. The terminal 74 issecured to the casing 66. llts connection with the armature`60 may betraced through the conductive casings 66 and 58 and through the plug 64and through the Wire 62 to the armature 60.

It is evident, that when the armature 68 is moved under -the influenceofV an external magnetic field, it may make The casing 58 is preferablylled with an hydraulic l fluid to prevent undesired vibration of lthearmature 6i) and to provide suitable damping for the unit. VWhen theswitching unit 52 is placedl annular amasar that one of the magnets 28passes the switch 52 as the `assembly is rotated, the shift orvariationin the ilux due to the channel 26 and the oiset arrangement ofthe magnet 28 causes the armature control portionv 60a to move intoengagement with the iixedcontac-tp and out of engagement with thefixed'contact 70.

Therefore, each time a channel 26 and its associated magnet 28 sweeps byone of the switching units as the assembly is rotated, it actuates'thatunit lfrom one operating condition to the other. rEach one of theplurality of switching units 52 may be operated anydesired' number oftimes during each rotation of the turntable 16, as determined by thenumber of channels 26 and the permanent magnets v28 respectivelyassociated with those channels.

As noted previously, the provision of the channels 26 and of the offsetmagnets 28 provides precisely located and well-defined shifts orvariations in the magnetic ilux in the air gap 24 so that the actuationof the switches can be accurately controlled and timed. Moreover, theactuation of the switches is positive and there is no vibration in theswitch armatures. This reduces ext-raneous noise to a minimum andsharply defined switching action is obtained.

The apparatus constituting this invention has certain importantadvantages in addition to those described previously. yOne advantageresults from the 'fact that the apparatus can be disposed in any otherplane than the horizontal pl-ane. This advantage is obtained because'the armature 60 is held against the contacts 68 and 70 by a force inthe order of 50 t-o 100 Gs and a gravitational force of 1 G would havelittle effect on-such a holding force. i

Another advantage results `from the fact that all leakage iiux lisproduced internally in the air gap between the annular members 18 and20. This results `from the closed loops provided for the members 18 and20. Since relatively little leakage flux can traverse the area outsideof the members 18 and 20, electrical leads andV even magneticallyreceptive equipment c-an be disposed in the immediate vicinity of theapparatus constituting this invention without having any undesirablesignals. induced in such leads and magnetically receptive equipment.

Although this application has been disclosed and illustrated withreference to particular applications, the principles involved aresusceptible of numerous other applications which Will be apparent topersons skilled in the art. The invention is, therefore, to be limitedonly as indicated fby the scope of the appended claims.

' I claim:

l. A switching Iassembly including: means including first and secondwalls spaced to define a continuous air gap between the walls and havingcontours to define a displacement in sa-id air gap in at least oneposition along said walls yand having properties to produce in said airgap a field exhibiting variationsat the position of displacement, meanscoupled to the first and second walls for producing a magnetic iield inthe air gap in accordance with the disposition of the air gap latsuccessive positions, switching means disposed l-in said air gap andresponsive to such variations Iin said field to be actuated from oneoperating condi-tion to another, and means for producing relative motionbetween said Walls land said switching means to bring said switchingmeans period- -ically under the inuence of the variations in the fiield.

2. A magnetically controlled switching assembly including: means'including first and second walls spaced 'to define a continuous ai-r,gap between the walls and provided with -contours in at least onewallto define a walls and having properties to produce in said gap magneticflux at successive positionsjalongsaid air Agap inthe direction between.the walls and to produce variations in Ysuch magnetic -ux at theposition of displacement and in accordance with such displacement, meanscoupled magnetically to the first and second walls for producing amagnetic flux in the air gap in accordance with the disposition of theair gap at successive positions, switching means disposed -in said airgap and including an armature repsonsive to suchvariations in themagnetic flux to control the operating condition ofjsaid switchingmeans, and means for producing relative motion between the walls andsaid switching means to bring said armature periodically under theinfluence of the variations in the magnetic iiux. i

3. A magnetically controlled switching-assembly including: rotatablemeans including first and second walls spaced 'from each other in adirection transverse to the plane of rotation to define an air gapextending in the direction of rotation and provided with contours todeline a displacement in the air gap at a particular position and in thetransverse direction, means including the firs-t and second walls forproducing a magnetic flux across said air gap in accordance with thepositioning of the air gap in the transverse direction -to obtainvariations in the magnetic flux at the position of displacement of theair gap `and in accordance with such displacement, at least onestationary switching unit disposed in said annular air gap and includingan armature constructed at least in part of magnetic material yandresponsive to such variations in the magnetic flux to con-trol thevoperating condition of said switching unit, and means for rotating saidrotatable means to produce relative mo.- tion Ibetween said magneticflux and said switching unit to bring said armature periodically underthe influence of the variations in the magnetic flux.

4. A magnetically controlled switching assembly including: meansincluding first and second walls spaced to define a continuous ai-r gapbetween t-he walls and having contours in at least one wall to define adisplacement in said air gap -in at least one position along said wallsAand in a direction transverse to the walls and having properties toproduce in said `air gap magnetic flux extending between the walls toobtain variations in the magnetic flux at the position of displacementand in accordance with such displacement, at least one switching unit-disposed in said air gap, said switching unit including .a resilientlymounted armature and at least one fixed contact engageable by saidarmature underthe control of such variation in the magneticux, and meansfor producing relative motion between said walls and said switching unitin a .direction transverse to the displacement in said air gap to bringsaid armature periodically under the influence of such variations insaid magnetic ux.

5. A magnetically controlled switching assembly in cluding: meansincluding-first and second walls spaced to define a continuous yair gapbetween the walls and provided with contours in at least one wall todefine a displacement in said air gap in the direction between thewal-ls and having properties to produce in said air gap magnetic flux atsuccessive positions along said air gap in the direction between thewalls and to produce variations in such magnetic liux Iat the positionof displacement and in acc-ordance with such displacement, at least oneswitching unit disposed in said air gap, said switchingu-nit including ahousing of non-magnetic material, and said switching unit furtherincluding a resiliently mounted armature and at least one fixed contactengageable by said armature under the control of such variations in themagnetic Iflux, a damping fluid included in said housing to inhibitvibrations of said armature, and means for producing relative motionbetween said |walls and said switching unit in a direction `transverseto the displacement in the lair gap to 'bring'lsaid 7 armatureperiodically under the influence of said variations in said magneticflux.

6. A'magnetically controlled switching assembly including: means fordefining an air gap and including first and second walls spaced todcline a continuous air gap between the walls and having contours in atleast one wall to define a displacement in said air gap in at least oneposition along said Walls and in a direction transverse to the walls andlhaving properties to produce in said air gap magnetic iiux extendingbetween the Walls to obtain variations in the magnetic flux at theposition of displacement and in accordance with such displacement, atleast one switching unit disposed in said air gap, said switching unitincluding a housing of non-magnetic material and a pair of fixedcontacts supported in said housing at mutually spaced positions, saidswitching unit further including an armature resiliently supported insaid housing and having a contact portion ex-tending -between said iixedcontacts and further having a magnetic portion responsive to saidmagnetic liux in said air gap to cause said contact portion to engageone of said fixed contacts and responsive to said variations in Ithemagnetic fiux to cause said contact portion to engage the other of saidfixed contacts, a damping liquid included in said housing to inhibitvibrations of said armature, and means for producing relative motionbetween said walls and said switching unit in a direction transverse tothe displacement in said air gap to bring the magnetic portion of saidarmature periodically under the infiuence of said variations in saidmagnetic iiux.

7. A magnetically controlled switching assembly including: a pair ofannular members supported in concentric relation to define an annularair gap therebetween and provided with contours to produce adisplacement in said air gap in at least one position in a directionperpendicular to said annular direction, means associated with saidannular members for producing in said annular air gap a magnetic fluxexhibiting variations at the position of displacement in said air gapand in accordance with such displacement, at least one switching unitdisposed in said annular air gap and including an armature constructedat least in part of magnetic material and responsive to such variationsin the magnetic ux to control the operating condition of said switchingunit, and means for producing relat-ive motion between said switchingunit and said pair of annular members in the annular direction to bringsaid armature periodically under the influence of the variations in themagnetic flux.

define an annular air gap therebetween, means associated with saidannular members for producing in said annular air gap a magnetic flux ina direction substantially perpendicular to the annular direction, meansassociated lwith said annular members for producingta displacement insaid air gap in at least one position and in a direction substantiallyperpendicular to said annular direction to obtain flux variations atthat posi-tion in said air gap in a direction substantiallyperpendicular to said annular direction and in accordance with thedisplacement in the air gap, at least one stationary switching unitdisposed in said annular air gap and including an armature constructedat least in part of magnetic material and responsive to such variationsin the magnetic flux to control the operating condition of saidswitching unit, and means for rotating said rotatable means to producerelative motion between said switching unit and said pair of annularmembers to bring said armature periodically under the inuence of thevariations in the magnetic flux.

`9.7A magnetically ycontrolled switching assembly including: first andsecond annular members each composed of magnetic material and the innerdiameter of said annular member exceeding the outer diameter of saidsecond annular member, one of said annular members having at least onetransverse channel of a selected width and depth formed in a peripheraledge thereof at a selected angular position and extending axially alongvsaid peripheral edge, rotatable means for supporting said annularmembers in concentric relation to define an annular air gaptherebetween, means associated with said annular members for producingin said annular air gap a. magnetic iiux exhibiting diametricaldisplacements .at a position corresponding to the angdllar position ofsaid channel, at least one stationary switching unit disposed in saidannular air gap and including an armature constructed at least in partof magnetic material and responsive to such displacements in themagnetic flux in said ai-r gap to control the operating condition ofsaid switching unit, and means for rotating said rotatable means toproduce relative motion between said switching unit and said pair ofannular members to 4bring said armature periodically under the iniiuenceof said displacements in said magnetic flux,

l0. A magnetically controlled switching assembly including: first andsecond annular members each composed 0f magnetic material and the innerdiameter of said lfirst annular member exceeding the outer diameter ofsaid second annular member, one of said annular members having laplurality of transverse channels each of a selected width and depthformed in a peripheral edge thereof and at selected angular positionsand each such channel extending axially alo-ng such peripheral edge,rotatable means for Isupporting said annular members in mutually fixedconcentric relation to define an annular air gap therebetween, meansassociated with said annular members for producing a magnetic iiux insaid yair gap and including portions extending radially into said airgap lat respective angular positions corre` sponding to said `angularpositions of said channels and cooperating with said channels to producediametrical displacements in said magnetic flux, at least one stationaryswitching unit disposed in said air gap and including an armatureconstructed .at least in part of magnetic material and responsive tosuch displacements in the magnetic iiux to control the operatingcondition of said switching unit, and means for rotating said rotatablemeans to produce relative motion between said switching unit a-nd saidpair of annular members to bring said 'armature periodically under theinfluence of said dis- 'placements in said magnetic liux.

1l. A magnetically controlled switching assembly including: first andsecond annular members each composed of magnetic material and the innerdiameter of said first annular member exceeding the outer diameter ofsaid second annular member, Vone of said annular members having aplurality of transverse channels each of a selected width and depthformed in a peripheral edge thereof at `selected angular positions andeach such channel extending axially along such peripheral edge, aturntable composed of non-magnetic material supporting said annularmembers in mutually fixed concentric relation to define an annular airgap therebetween, said annular members being so supported in a planespaced from the plane of said turntable, electric motor means coupled tosaid turntable Ifor imparting rotational motion to said turntable and tosaid annular members, means associated with said annular members forproducing a magnetic ilux in said annular air gap and including portionsextending radially into said air gap at respective angular positionscorresponding to said angular positions of said channels and cooperatingwith said channels to produce radial displacements in said magneticflux, atleast one stationary switching unit vdisposed in said annularair gap land including an armature constructed at least in part ofmagnetic material and responsive to such displacements in the magneticflux to control the operating condition of said switching unit, andmeans for rotating said rotatable means to produce relative motionbetween said switching unit and said pair of annular members to bringsaid armature periodically under the inliuence of said displacements insaid magnetic flux.

12. A magnetically controlled switching assembly including: first andsecond annular members each composed of magnetic material and the innerdiameter of said first annular member exceeding the outer diameter ofsaid second annular member, said second annular member having aplurality of transverse channels each of a selected width and depthformed in a peripheraledge thereof at selected angular positions andeach such channelextending axially along such peripheral edge, rotatablemeans positioned under said annular members for supporting said annularmembers in mutually fixed nested concentric relation to define anannular air gap therebetween, a plurality of U-shaped permanent magnetsmountedo'n said rotatable means at said selected angular positions ofsaid transverse channels, each of said magnets having a pairVofs-pacedpoles extending upwardly from said rotatable means into respectiveengagement with said first andisecond annular members, and saidpermanent magnets being offset radially with respect to said annularmembersso that one of said poles is displaced radially away from saidrst annular member into said annular air gap and the. other of saidpoles is displaced radially toward said second annular member away fromthe corresponding one of said` channels therein, said permanent magnetsproducing a magneticux in said annular air gap which exhibits radialvariations at positions corresponding to the angular positions of saidchannels, at least one stationary switching unit disposed in saidannular air gap and including an armature constructed at least in partof magnetic material and responsive to such variatio'ns in the magneticliux to control the operating condition of said switching unit, andmeans for rotating said rotatable means to produce relative motionbetween said switching unit and said pair of annular members so' as tobring said armature periodically under the iniiuence of said variationsin said magnetic flux.

13. A switching assembly for controlling at least one stationaryswitching unit, said assembly including: a pair of annular memberssupported in concentric relation to define an annular air gaptherebetween for receiving the switching unit and provided with relativeco'ntours to produce an axial displacement in the' air gap in at leastone position along the air gap, permanent magnet means associated withsaid annular members Vfor producing in said annular air gap a magneticflux extending in an axial direction at successive positions along theair gap and exhibiting axial variations in at least the position ofaxial displacement in said air gap, and means for rotating said annularmembers and said permanent magnet means to produce relative motionbetween the magnetic fiux in the air gap and the switching unit to bringthe switching unit periodically under the influence of the variations inthe magnetic ux in said air gap.

14. In a switching unit, a casing made from an electrically conductivematerial, a plug made from an electrically conductive material anddisposedat one end of the casing, a wire dispo'sed in the casing andextending from the plug, an armature made from a soft magnetic materialand coupled to the wire for a pivotal movement, a first electricalcontact carried by the armature at the opposite end of the .armature fora lpivotal movement of the contact with the armature, and a seco'ndelectrical l contact supported by the casing but insulated therefrom l5.Inra switching unit, a casing having a first portion made-from anelectrically conductive material and having a second portion also madefrom an electrically conductive material, a plug made from electricallyconductive material disposed in the casing at one end of the iirstelectrically conductive portion, a wire extending fro'm the plug, anarmature coupled to the wire at one end for pivotal movement at theother end and made from a material having magnetizable properties, afirst electrical contact carried by the armature at the free end of thearmature, an insulating plug disposed in the casing at one end o'f thesecond portion of the casing, a second electrical contact extendingthrough the insulating plug and disposed in the casing relative to thefirst electrical contact to engage the first contact upon a pivotalmovement lof -the armature, the end of said second electrical contactextending through the insulating plug fo'rming a first terminal oftheswitching unit mounted in electrically conductive contact with thesecond electrically conductive portion of said casing to form aconductive path through the switching unit when the second co'ntactengages the first contact, the conductive path being from the secondterminal through the second portion of the casing, the first portion ofthe casing, the electrically conductive plug, the wire, the armature,and the engaged contacts to' the first terminal.

16.- The assembly set forth in claim 3 in which a plurality ofadditional switching units corresponding to the first switching unit aredisposed in the annular air gap lfor response to the variations in themagnetic flux.

17. 'Ihe assembly set forth in claim 4 in which the first and secondwalls are provided with contours to define a plurality of displacementsin the air gap and in which a plurality of switching units correspondingto the first switching unit are disposed in the air gap and are providedwith resiliently mounted armatures to bring the armatures periodicallyunder the inuence of the variations in the magnetic flux resulting fromthe displacements in the air gap.

18. The assembly set fo'rth in claim 9 in which one of the annularmembers is provided with a plurality of transverse channels and in whicha plurality of stationary swltching units are disposed in the air gapand are provided with armatures responsive to the variations in themagnetic flux at the transverse channels.

19. In a switching unit, a casing being made at least 1n part from anelectrically conductive material and forming an envelope for theswitching unit, a first output terminal connected to the conductivematerial of the casing, a movable armature made from a magnetic andconductive material and electrically coupled at one end to theelectrically conductive material of said casing, a first electricalcontact carried by the armature at the other end of the armature, astationary second electrical contact supported by said casing butinsulated from the co'nductive material of said casing so as to beengaged by said first electrical contact upon a movement of saidarmature whereby a conductive path is established through the conductivematerial of the casing and through said first and said second contacts,and a second puttput terminal electrically connected to said secondco'n- 20. In a switching unit, a casing being made at least rn part froman electrically conductive material and formlng an envelope for theswitching unit, a rst output terminal connected to the conductivematerial of the casing, a plug made from an electrically conductivematerial and disposed in one end of the casing in electrical contactwith the conductive material of the casing, a flexible and conductivewire disposed in the casing and extending from the plug, an armaturemade from a magnetic and conductive material and coupled at one end tothe wire for a pivotal movement, a first electrical contact carried bythe armature at the other end of the armature, a stationary secondelectrical contact supported by said casing but insulated from theconductive material of said casing and positioned in said casing so asto be engaged by said rst electrical contact upon a movement of saidarmature whereby a conductive path is established through the conductivematerial of the casing and through said first and said second contacts,a plug made from an insulating material at the other end of the casingfor supporting said second contact, and a second output terminalsupported Vby said insulating material plug and electrically connectedto said second contact.

21. A switching assembly, including, a plurality of switches arranged ina circle, each of said switches having a movable armature, a circularrotor concentrically positioned in the circle of said plurality ofswitches and having a peripheral surface spaced from said plurality ofswitches to form an annular space between said rotor and said pluralityof switches, means coupled to said rotor for rotating said rotor, andactuating means supported on said rotor in the annular space formedbetween the peripheral surface of said rotor and said plu? rality ofswitches and spaced from said plurality of switches for successivelymoving the armatures of said switches one after another without touchingthem as said rotor rotates said actuating means adjacent thereto.

22. A high speed cyclically operated switching assembly, including, aplurality of switches each including a movable armature having a normaland an operated position, means for supporting said plurality ofswitches in a circle of predetermined radius, a circular memberpositioncd concentrically in the circle ofsaid plurality of switcheshaving a peripheral surface spaced at a predetermined distance from saidplurality of switches to form an annular space between the peripheralsurface of said member and said plurality of switches, actuating meanssupported on said circular member in the `annular space-between theperipheral surface of said member and said plurality of switches foractuating any one of said switches adjacent which it is positioned tomove the armature of said actuated switch from its normal to itsoperated positions, said actuating means being spaced from any one ofsaid plurality of switches adjacent which it is positioned so as not totouch any one of said switches at any relative position between saidcircular member and said switches, and means for establishing relativemotion between said switches and said member to cause said actuatingmeans to cyclically operate said switches.

References Cited in the file of this patent UNITED STATES PATENTS2,112,214 Tognola Mar. 22, 1938 2,310,138 Whittaker Feb. 2, 19432,310,357 Edelman Feb. 9, 1943 2,488,373 Burton Nov. 15, 1949 2,508,508Garvin May 23, 1950 2,547,003 Hastings Apr. 3, 1951 2,550,605 SchenckApr. 24, 1951 2,609,464 Brown et al. Sept. 2, 1952 2,803,720 Mason Aug.20, 1957 2,845,506 De Lucia Iuly 29, 1958 FOREIGN PATENTS 520,540Germany Mar. l2, 1931 720,957 France Dec. 12, 1931

